The Visible Human Project (VHP) of the National Library of Medicine has catalyzed the development of advanced visualization software that has aided in anatomy education and has been an invaluable resource to biomedical researchers. It has aided in the development of numerous technologies, with applications spanning from improving imaging technology to simulating surgical procedures. Our long-term goal is to develop a comparable "Audible Human Project" (AHP). This would accurately simulate the production, transmission and noninvasive measurement of naturally-occurring sounds associated with cardiovascular, pulmonary and gastro-intestinal function. It would also model externally introduced sounds, for example via percussion at the skin surface. Constructed from a baseline of acoustic characteristics recorded for specific human subjects with specific pathologies and sensors, the Audible Human model extrapolates the acoustic characteristics for virtual patients with different pathologies and anatomical dimensions. It also simulates access to the pathologies of virtual patients using different acoustic sensors from the original recording sensor. Such a comprehensive tool would have a significant impact on medical education and research. It could catalyze the development of new inexpensive, portable auscultative methods, as well as more advanced multimode acoustic imaging modalities. From an educational perspective, recent studies have emphasized the continued importance of skilled auscultation in medicine and the fact that this skill is in decline among younger physicians. The AHP could help provide a more effective educational experience. A student would not just listen to audio recordings, but would be able to interactively vary anatomy and pathology, as well as sensor position, type and contact pressure, so as to hear, "see" and "feel" (in a haptic environment) the results and associate them with quantifiable metrics. The goal of this 5-year R01 application (which builds upon a R03 pilot grant that received a priority score of 126) is to develop and experimentally validate comprehensive male and female upper torso acoustic models capable of representing healthy and specific pathological conditions, including pneumothorax, pleural effusion, hydrothorax, mucous plugs, emphysema, obesity and masses (tumors) in the lung. These models will simulate breath sound generation, transmission and measurement via contact and non-contact sensors on the torso surface. They will also simulate the transmission and measurement of externally introduced sound via introduction of sound at the glottis into the bronchial airway tree or via percussion on the torso surface. In order to achieve this goal, the following specific aims will be undertaken: (1) Develop the AHP computer simulation model to simulate breath sound generation, how specific lung pathologies alter the acoustic environment, and how different contact acoustic sensor dynamics alter measurements;(2) Perform mechanical phantom model studies to evaluate and refine the AHP computer model;(3) Perform canine animal model studies to further refine the AHP computer model;and (4) Perform human subject studies to validate the AHP computer model. PUBLIC HEALTH RELEVANCE: The envisioned comprehensive Audible Human Project, like the Visible Human Project, will be relevant to both medical research and education. It would significantly impact public health by catalyzing the development of improved medical diagnostic techniques and by providing a more effective educational paradigm for teaching stethoscopic skills, which are in decline as noted in recent studies. The student would not just listen to audio recordings but would be able to interactively vary anatomy and disease, as well as stethoscope characteristics and hear, "see" and "feel" the results.